| Kazutaka Sakai | Telecommunication System Group, |
| Kagehiro Yamamoto | Telecommunication System Group, |
| Kiichirou Taima | Hitachi Telecom(USA), Inc. |
| Ichirou Ishikawa | Telecommunication & Information Infrastructure Systems, |
Hitachi has developed a variety of high-speed optical transmission systems for implementing ring networks that meet the needs of large-capacity backbone networks. (1) The 10-Gbit/s SONET (synchronous optical network)/SDH (synchronous digital hierarchy) and 2.4-Gbit/s SDH optical transmission systems, compliant with SONET and SDH international standards, use a bi-directional line switched ring or a unidirectional path switched ring switching function to provide highly reliable ring networks. (2) The dense wavelength division multiplexing system supports a transmission capacity of up to 1.28 Tbit/s (10 Gbit/s per wavelength × 128 wavelengths) and provides flexibly expandable networks using an optical add-drop multiplexer function that can drop or add a multiplexed wavelength at a mid-point node. (3) The transparent transponder multiplexer system can transparently multiplex and transmit operation and management information from a low-speed interface side to a high-speed interface side, thereby flexibly accommodating various devices into high-speed networks.
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Information & Telecommunication Systems |
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Telecomunication & Network Systems |
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The Hitachi Hyoron (Japanese Only) |
SONET, SDH, DWDM, Transmission System, Transparent
